(55 days)
Vantage Orian 1.5T systems are indicated for use as a diagnostic imaging modality that produces cross-sectional transaxial, coronal, sagittal, and oblique images that display anatomic structures of the head or body. Additionally, this system is capable of non-contrast enhanced imaging, such as MRA.
MRI (magnetic resonance imaging) images correspond to the spatial distribution of protons (hydrogen nuclei) that exhibit nuclear magnetic resonance (NMR). The NMR properties of body tissues and fluids are:
·Proton density (PD) (also called hydrogen density) ·Spin-lattice relaxation time (T1) ·Spin-spin relaxation time (T2)
·Flow dynamics
·Chemical Shift
Depending on the region of interest, contrast agents may be used. When interpreted by a trained physician, these images yield information that can be useful in diagnosis.
The Vantage Orian (Model MRT-1550) is a 1.5 Tesla Magnetic Resonance Imaging (MRI) System. The Vantage Orian uses 1.4 m short and 3.8 tons light weight magnet. It includes the Pianissimo™ technology (scan noise reduction technology). The design of the gradient coil and the WB coil of the Vantage Orian 1.5T provides the maximum field of view of 55 x 50 cm. The Model MRT-1550/AC, AD, AG, AH includes the standard gradient system and Model MRT-1550/AK, AL, AO, AP includes the XGO gradient system.
This system is based upon the technology and materials of previously marketed Canon Medical Systems MRI systems and is intended to acquire and display cross-sectional transaxial, coronal, sagittal, and oblique images of anatomic structures of the head or body. The Vantage Orian MRI System is comparable to the current 1.5T Vantage Orian MRI System (K202767), cleared January 15th, 2021.
The provided document is a 510(k) summary for the Canon Medical Systems' Vantage Orian 1.5T MRI system, specifically for an extension of the Compressed SPEEDER (2D) maximum acceleration factor. The study described focuses on demonstrating that the extended acceleration factors (3.0 and 4.0) maintain equivalent performance to the previously cleared acceleration factor of 2.5.
Here's a breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative acceptance criteria in numerical form for metrics like sensitivity, specificity, or image quality scores. Instead, the acceptance criterion for the study appears to be a qualitative equivalence between the higher acceleration factor images and the predicate 2.5 acceleration factor images.
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| No clinically-relevant difference in preference between the predicate Compressed SPEEDER (2D) images (acceleration factor 2.5) and the higher acceleration factor (3.0 and 4.0) images. | The study "demonstrated no clinically-relevant difference in preference between the predicate Compressed SPEEDER (2D) images with acceleration factor of 2.5 when compared to the higher acceleration factor (shorter scan time) images." |
| Performance equivalence to the commercially available predicate device. | "The results of the testing demonstrated that Compressed SPEEDER (2D) with the acceleration factors of 2.5, 3.0 and 4.0 performed at the equivalent performance level to the commercially available predicate device." |
Note: The document describes a preference study rather than a study assessing diagnostic accuracy directly. The acceptance criteria are therefore stated in terms of preference and equivalent performance.
2. Sample Size and Data Provenance
- Sample Size for Test Set: 34 studies
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. It mentions "volunteer clinical imaging" which suggests prospective data collection.
3. Number of Experts and Qualifications for Ground Truth
- Number of Experts: Three board-certified radiologists per anatomy.
- Qualifications of Experts: Board-certified radiologists. (No mention of years of experience).
4. Adjudication Method
The document describes a "Human observer study" where radiologists assessed "preference." It does not specify a formal adjudication method (like 2+1 or 3+1 consensus) for establishing a single "ground truth" for the test set. Instead, it suggests individual preferences were aggregated to determine if there was a clinically relevant difference in preference. The phrasing "demonstrated no clinically-relevant difference in preference" implies that a consensus or aggregation of these preferences led to this conclusion.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study assessing human readers' improvement with AI vs. without AI assistance was not explicitly described. This study was a comparison of different acceleration factors using the same AI reconstruction (Compressed SPEEDER 2D). The AI (AiCE Reconstruction Processing Unit) is a component of the device, and the study assessed the impact of varying one of its parameters (acceleration factor) on image preference. It was not a comparison of human readers using AI versus not using AI.
6. Standalone (Algorithm Only) Performance
The study was a "Human observer study," meaning it involved human interpretation of the images produced by the algorithm. It does not explicitly mention a standalone (algorithm only) performance evaluation without human-in-the-loop. The focus was on how humans perceive the images generated by the different acceleration factors.
7. Type of Ground Truth Used
The "ground truth" in this context is indirect. It is not pathology, outcomes data, or a pre-established "correct diagnosis." Instead, the "ground truth" for the performance comparison was the preference of board-certified radiologists for one set of images (higher acceleration) compared to another (predicate 2.5 acceleration). The goal was to establish that there was no clinically relevant difference in preference, suggesting visual equivalence.
8. Sample Size for Training Set
The document does not provide information on the sample size used for the training set of the AiCE Reconstruction Processing Unit. The study described focuses on validating the extension of an existing feature (Compressed SPEEDER 2D) and implies no changes to the core AiCE software or hardware.
9. How Ground Truth for Training Set Was Established
The document does not provide information on how the ground truth for the training set of the AiCE Reconstruction Processing Unit was established.
§ 892.1000 Magnetic resonance diagnostic device.
(a)
Identification. A magnetic resonance diagnostic device is intended for general diagnostic use to present images which reflect the spatial distribution and/or magnetic resonance spectra which reflect frequency and distribution of nuclei exhibiting nuclear magnetic resonance. Other physical parameters derived from the images and/or spectra may also be produced. The device includes hydrogen-1 (proton) imaging, sodium-23 imaging, hydrogen-1 spectroscopy, phosphorus-31 spectroscopy, and chemical shift imaging (preserving simultaneous frequency and spatial information).(b)
Classification. Class II (special controls). A magnetic resonance imaging disposable kit intended for use with a magnetic resonance diagnostic device only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.